Bottom Line:
The preoperative target length was successfully achieved in all patients at a mean of 4.1 cm (range 1.8-6.5 cm).The mean duration of external fixation was 75.3 days (range 33-116 days) with the mean external fixation index at 19.2 days/cm (range 10.0-38.3 days/cm).Lengthening over plate is also applicable to children with open physis.

Background: The limb lengthening over plate eliminates the associated risk of infection with limb lengthening over intramedullary nail. We present our experience of limb lengthening in 15 patients with a plate fixed on the proximal segment, followed by corticotomy and application of external fixator.

Materials and methods: 15 patients (7 females, 8 males) were included in this consecutive series. The average age was 18.1 years (range 8-35 years). Fifteen tibiae and one femur were lengthened in 15 patients. Lengthening was achieved at 1 mm/day followed by distal segment fixation with three or four screws on reaching the target length.

Results: The preoperative target length was successfully achieved in all patients at a mean of 4.1 cm (range 1.8-6.5 cm). The mean duration of external fixation was 75.3 days (range 33-116 days) with the mean external fixation index at 19.2 days/cm (range 10.0-38.3 days/cm). One patient suffered deep infection up to the plate, three patients had mild procurvatum deformities, and one patient developed mild tendo achilles contracture.

Conclusion: Lengthening over a plate allows early removal of external fixator and eliminates the risk of creating deep intramedullary infection as with lengthening over nail. Lengthening over plate is also applicable to children with open physis.

Figure 4: (a) Clinical photograph of plate prominence with impingement on the skin. It resolved after plate adjustment and distal locking during second procedure. (b) The modified plate with a longitudinal slot between the proximal and distal locking holes. (c) Radiograph of a procedure done with the slotted plate. The unicortical screw through the slot in the distal segment keeps the plate close to the bone during the distraction period

Mentions:
There were four cases of septic arthritis of hip and one each of congenital short femur, proximal femur nonunion, and idiopathic chondrolysis of femoral head. The only patient in whom we lengthened the femur was the case with congenital short femur; for the other six with femoral shortening, we lengthened the tibia. Out of four patients with septic arthritis of hip, two underwent PSO at the intertrochanteric level, the mechanical axis of the limb remained aligned, and we lengthened the tibia to minimize complications at the knee joint because the hip was already affected. The other two patients were stable at the hip joint and the femur bone quality was not very good, so we lengthened the tibia to avoid a poor regenerate and complications at the hip and knee joint. The case with proximal femur nonunion treated by plating was plated and bone grafted and tibial lengthening was done over a plate because the plate used for nonunion was coming in the way of plate to be used for femoral lengthening andthe plate used for nonunion could have been exposed to the external fixator wires, thus risking infection. The single case of idiopathic chondrolysis underwent PSO at the intertrochanteric level, the mechanical axis did not have significant deviation, and tibial lengthening over a plate was done at the same sitting. We had one complication of plate prominence during the distraction period which impinged on the skin [Figure 4a]. We have tried to address this problem by modifying the conventional LCDCP with a longitudinal slot in between the proximal and distal locking holes (Pitkar, Pune, India) [Figure 4b and c]. The plate has a slot through which one unicortical screw is fixed to the distal fragment and the screw slides down along with the distal segment during lengthening. This ensures the plate close to the bone at all times and may also prevent deformity. Till today, we have lengthened six segments with this plate and we have not experienced any complications. The slot weakens the plate However, with a followup of a maximum of 1.5 years, with this new plate we have had no complications of implant failure of excess deformity. A biomechanical testing of the plate is required. The slot does not decrease near fixation because the plate comes in different slot lengths and we use the slot length based on the amount of shortening or the target length. So, a case with desired 4 cm lengthening will have a plate with 4 cm slot. Also, there is one unicortical screw through the slot in the distal segment, which may add to the stability.

Figure 4: (a) Clinical photograph of plate prominence with impingement on the skin. It resolved after plate adjustment and distal locking during second procedure. (b) The modified plate with a longitudinal slot between the proximal and distal locking holes. (c) Radiograph of a procedure done with the slotted plate. The unicortical screw through the slot in the distal segment keeps the plate close to the bone during the distraction period

Mentions:
There were four cases of septic arthritis of hip and one each of congenital short femur, proximal femur nonunion, and idiopathic chondrolysis of femoral head. The only patient in whom we lengthened the femur was the case with congenital short femur; for the other six with femoral shortening, we lengthened the tibia. Out of four patients with septic arthritis of hip, two underwent PSO at the intertrochanteric level, the mechanical axis of the limb remained aligned, and we lengthened the tibia to minimize complications at the knee joint because the hip was already affected. The other two patients were stable at the hip joint and the femur bone quality was not very good, so we lengthened the tibia to avoid a poor regenerate and complications at the hip and knee joint. The case with proximal femur nonunion treated by plating was plated and bone grafted and tibial lengthening was done over a plate because the plate used for nonunion was coming in the way of plate to be used for femoral lengthening andthe plate used for nonunion could have been exposed to the external fixator wires, thus risking infection. The single case of idiopathic chondrolysis underwent PSO at the intertrochanteric level, the mechanical axis did not have significant deviation, and tibial lengthening over a plate was done at the same sitting. We had one complication of plate prominence during the distraction period which impinged on the skin [Figure 4a]. We have tried to address this problem by modifying the conventional LCDCP with a longitudinal slot in between the proximal and distal locking holes (Pitkar, Pune, India) [Figure 4b and c]. The plate has a slot through which one unicortical screw is fixed to the distal fragment and the screw slides down along with the distal segment during lengthening. This ensures the plate close to the bone at all times and may also prevent deformity. Till today, we have lengthened six segments with this plate and we have not experienced any complications. The slot weakens the plate However, with a followup of a maximum of 1.5 years, with this new plate we have had no complications of implant failure of excess deformity. A biomechanical testing of the plate is required. The slot does not decrease near fixation because the plate comes in different slot lengths and we use the slot length based on the amount of shortening or the target length. So, a case with desired 4 cm lengthening will have a plate with 4 cm slot. Also, there is one unicortical screw through the slot in the distal segment, which may add to the stability.

Bottom Line:
The preoperative target length was successfully achieved in all patients at a mean of 4.1 cm (range 1.8-6.5 cm).The mean duration of external fixation was 75.3 days (range 33-116 days) with the mean external fixation index at 19.2 days/cm (range 10.0-38.3 days/cm).Lengthening over plate is also applicable to children with open physis.

Background: The limb lengthening over plate eliminates the associated risk of infection with limb lengthening over intramedullary nail. We present our experience of limb lengthening in 15 patients with a plate fixed on the proximal segment, followed by corticotomy and application of external fixator.

Materials and methods: 15 patients (7 females, 8 males) were included in this consecutive series. The average age was 18.1 years (range 8-35 years). Fifteen tibiae and one femur were lengthened in 15 patients. Lengthening was achieved at 1 mm/day followed by distal segment fixation with three or four screws on reaching the target length.

Results: The preoperative target length was successfully achieved in all patients at a mean of 4.1 cm (range 1.8-6.5 cm). The mean duration of external fixation was 75.3 days (range 33-116 days) with the mean external fixation index at 19.2 days/cm (range 10.0-38.3 days/cm). One patient suffered deep infection up to the plate, three patients had mild procurvatum deformities, and one patient developed mild tendo achilles contracture.

Conclusion: Lengthening over a plate allows early removal of external fixator and eliminates the risk of creating deep intramedullary infection as with lengthening over nail. Lengthening over plate is also applicable to children with open physis.